Transcatheter aortic valve replacement (TAVR) is a treatment for stenosis of the aortic valve. A stenotic aortic valve is narrowed, restricting blood flow from the heart and increasing the potential for heart failure. TAVR is a minimally invasive approach to implanting an artificial heart valve inside a stenotic aortic valve.
During the TAVR procedure, a cardiologist inserts a tube (catheter) through an artery in the groin (transfemoral approach) or a small incision between the ribs (transapical approach). An artificial valve is compressed and fed through the catheter until it reaches the aortic valve. A balloon expands the artificial valve within the patient's stenotic aortic valve, essentially crushing the existing valve, and the catheter is removed. The new valve replaces the old, increasing blood flow throughout the body. A TAVR procedure developed by Edwards Lifesciences PVT, Inc. is described in U.S. Pat. No. 8,002,825 (Implantable Prosthetic Valve for Treating Aortic Stenosis), which is incorporated herein by reference.
Proper alignment of the artificial valve within the stenotic aortic valve is critical to the success of the TAVR procedure. The artificial valve should be positioned as exactly as possible on the crushed stenosed valve, parallel with the aortic annulus. Further, correct alignment of the imaging machines used by the cardiologist in relation to the patient's heart valve is critical to achieving the proper alignment of the artificial valve itself. Traditionally, a cardiologist may use high resolution fluoroscopy and/or cineradiography to view the aortic valve. In such imaging, dye is injected into the aorta, causing the valve to be perceived as a somewhat fuzzy white line on the imaging screen. The cardiologist then attempts to position the imaging machine perpendicular to the valve. Because of the innate imprecision of this method, the cardiologist may need to perform multiple x-ray shots (involving the same number of dye injections). This lengthens the duration of the procedure and increases the risk of complications to the patient.
The TAVR ventricular catheter of the present disclosure aids in the positioning of the C-arm of the imaging machines during a transfemoral TAVR procedure. The catheter is comprised of a hollow resilient tube through which a stiff wire releasably extends. When the wire is extended through the catheter, the catheter conforms to the shape of the wire such that it may be passed through the aortic artery. Once through the artery, the catheter may be deployed by removing the wire, at which point the distal end of the catheter becomes generally circular or oval ring that is positionable adjacent to and snugly beneath the existing stenotic valve. The distal circle can then be used to position the x-ray C-arm in position perpendicular to the aortic valve annulus. The proper C-arm angle is obtained when the distal horizontal circle no longer appears as a circle or ellipse, but as a straight line. This line also identifies the location for optimal valve positioning before valve deployment. The cine picture of this can be stored on a second monitor screen for reference during the actual valve positioning.
For purposes of summarizing the invention, certain aspects, advantages, and novel features of the invention have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any one particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.